JPH0827678B2 - Key top structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a keytop structure, and more particularly to a keytop structure which constitutes a push-down portion of a push button switch provided as an external switch for input operation of various terminal devices.

[0002]

2. Description of the Related Art Conventionally, an external switch provided for input operation of various terminal devices is a molded key top as a pressing portion, and a restoring load that acts by pressing this key top and returns to its original shape when the pressing force is removed. A push button switch including a contact rubber having a carbon contact made of an elastic molding material such as silicone rubber is widely used for the purpose. As a key top structure, instead of providing an independent key top for each key, in the layout of the operation panel (keyboard), it is divided into blocks (groups) by function or by column, and within the same block (in a group). ) Key tops are integrally molded to reduce the number of parts and the cost of assembly in consideration of the number of parts. For this reason, an elastic part whose width and thickness are as small as possible is provided from the side wall of the key top so as not to adversely affect the molding process, and the elastic part is connected to the runner (integrally molded) so that each pusher is pushed by the runner. The process is such that the buttons are integrated.

[0003]

In this conventional push button switch, since a plurality of key tops are integrally molded, the cost of the molding die is increased and the molding temperature, molding pressure, etc. in molding are molded. The conditions were strict and it was necessary to give due consideration to quality control. Further, since a plurality of key tops are integrated, there is a problem that the parts cannot be diverted to other models unless the key tops have the same interval (key pitch).

The object of the present invention is to solve the above-mentioned problems,
It is to provide an inexpensive key top with high versatility, which allows the molding conditions to be greatly relaxed, unnecessary consideration for quality control, and can be used for other models.

[0005]

The key top structure of the present invention is a key top structure of a push button switch as an external switch for performing an input operation of a terminal device.
A key top having four symmetrical side wall surfaces that are integrally molded from an elastic molding material and expand downward, and a key top that extends from the bottom of the four side wall surfaces in four directions at right angles to each other, and the stretching directions are opposite to each other. A pair of end portions are provided with a first mounting portion in which a plurality of pins are arranged at a predetermined pitch in the extending direction, and the plurality of pins are fitted in the other pair of end portions in which the extending directions are opposite to each other. And four elastic arms formed of an elastic molding material and provided with a second mounting portion having a plurality of fastening holes for wearing and fixing.

The key top structure of the present invention is the above first
At least one of the plurality of pins of the attachment portion of the second
It is characterized in that the key tops are fitted into the engagement holes and the plurality of key tops are combined and developed in a rectangular or rectangular shape on a plane for operation.

[0007]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a plan view (a) and a sectional view (b) of a keytop structure according to an embodiment of the present invention. The push-button switch that is the target of the present embodiment is provided with a conductive contact portion (contact pattern) that is patterned and is insulated and separated on the substrate surface.
A switch type key that has a configuration having a contact rubber arranged so that the conductive contact portion (carbon contact point) facing the contact pattern when pressed is provided, and the circuit is opened and closed by pressing the key top. It has a top structure. The key top 12 is formed integrally with a molding material having elastic properties (for example, ABS resin), and is composed of a pressing portion 1 that an operator directly touches with a finger and presses down, and four symmetrical side wall surfaces 2 around the pressing portion 1. Four flat plate-like elastic arms 3 which are protruded from the lower part in four directions perpendicular to each other and whose width and thickness are reduced as much as possible so as not to adversely affect the molding.
a, 3b, 3c and 3d and a plurality of pins 4 projecting upward at arbitrary intervals at the ends of a pair of elastic arms 3a and 3b in the same direction and having a width wider than that of the elastic arms 3a and 3b. And mounting portions 5a and 5b as first mounting portions having a slightly larger thickness, and another pair of elastic arm portions 3 in the same direction.
c and 3d have attachment portions 6a and 6b provided at the tips thereof as second attachment portions and provided with engaging holes 7 into which the pins 4 are fitted. Length of the elastic arm portions 3a to 3d (side wall surfaces 2a to 2d
To the pin 4 or the engaging hole 7 of the mounting portions 5a, 5b and 6a, 6b closest to the above, is determined within the elastic limit in consideration of the characteristics of the molding material to be used, the push button pressing stroke and the number of operations. It is decided in consideration of the proper size based on the use in and the avoidance of fatigue fracture.

Next, the assembly procedure and the function of each part in this embodiment will be described.

First, the key top 12 is attached to the operation panel 10 having the button hole 8 and the guide 9. The size of the button hole 8 is smooth by the restoring force of the contact rubber without the corners of the upper surface contacting the guide 9 in the button hole 8 even if the push-down portion 1 of the key top 12 is pushed (obliquely pushed). It is determined by providing a clearance with the pressing portion 1 so as to return to the state before pressing.

Regarding the engagement between the key top 12 and the operation panel 10, the key top 12 is inserted into the button hole 8 of the operation panel 10 from the inner surface side of the operation panel 10, and the guide 9 around the button hole 8 is attached. The key top 12 is contacted and received. Further, in this state, the key top 12
5a to 5 provided at the ends of the elastic arms 3a to 3d
The entire key top 12 is brought into close contact with the operation panel 10 by the positioning rib 11 arranged on the operation panel 10 so as to include d. At this time, the key top 12 to be assembled is provided with mounting portions 5a and 5b provided with the pins 4 of adjacent key tops and a mounting portion 6a provided with the engaging hole 7 so as to secure the required key pitch 101 in advance. , 6b flatten the key top group (for example, 3 horizontal and 4 vertical) as many as necessary to fit the pin 4 into the engagement hole 7. By configuring the key tops in this way, in the single key tops, the print display of the depressed portion 1 must be performed for each key top, whereas the print display for all the key tops of the key top group can be performed in one step. It will be possible.

After the key top 12 is assembled into the operation panel 10, a contact rubber (not shown) for electrical connection having a dome-shaped restoration structure that operates by pressing the pressing portion 1 and an electrical connection with the contact rubber are provided. Are assembled in such a manner that the controlled circuit boards (not shown) are superposed in this order to obtain a finished product.

FIG. 2 is a diagram showing an operation example of an embodiment of the present invention.

In the present invention, in order to make the key pitch 101 variable, the pins 4 of the attachment portions 5a and 5b provided at the ends of the elastic arms 3a and 3b and the engagement holes 7 into which the pins 4 are fitted are attached. From the state of FIG. 2 (a) to (b),
The key pitch 101 indicated by P is P + p by shifting the engaging holes 7 one by one so as to extend to the state of (c).
The operation can be expanded by changing the (pin pitch) key pitch 101a and the P + 2p key pitch 101b.

[0014]

As described above, according to the present invention, the key top of the push button switch as the external switch of the terminal device is individually configured, and the molding die is greatly simplified to reduce the cost, and a single key top is provided. However, it is possible to connect the adjacent key tops in a chained manner, and it is possible to change the key pitch due to the structure in which the engagement position can be selected, and it is also possible to divert parts to other models with different key pitches. It has the effect of being able to.

[Brief description of drawings]

FIG. 1 is a plan view (a) and a sectional view (b) of a keytop structure according to an embodiment of the present invention.

FIG. 2 is a diagram showing an operation example of an embodiment of the present invention.

[Explanation of symbols]

 1 Depressed part 2a-2d Side wall surface 3a-3d Elastic arm part 4 Pins 5a, 5b Mounting part 6a, 6b Mounting part 7 Locking hole 8 Button hole 9 Guide 10 Operation panel 11 Positioning rib

Claims (2)

[Claims] 1. A key top structure of a push button switch as an external switch for performing an input operation of a terminal device, the key top having four symmetrical side wall surfaces that are integrally molded with an elastic molding material and expand downward. , A first mounting in which a plurality of pins are arranged in a flat plate shape in four directions perpendicular to each other from the bottoms of the four side wall surfaces, and a plurality of pins are arranged at a predetermined pitch in each of the pair of end parts in which the drawing directions are opposite to each other. Elastic molding in which a second mounting portion having a plurality of engaging holes into which the plurality of pins are respectively fitted and engaged and fixed is provided at the other pair of end portions in which the extending directions are opposite to each other. A key top structure comprising four elastic arms made of a material. 2. At least one of the plurality of pins of the first mounting portion is fitted into the engagement hole of the second mounting portion to combine the plurality of key tops into a rectangular or rectangular shape on a plane. The key top structure according to claim 1, wherein the key top structure is deployed and used.